That came after more than 6,500 flights were canceled on Thursday alone, a massive figure that sent delays and cancellations rippling to all corners of the nation. By mid-morning Thursday, moderate to severe schedule disruptions were being reported at most airports â?? big and small â?? from Georgia north through Maine.

"Yesterday saw 6,533 flights cancelled and another 4,605 delayed, which amounts to nearly half of the daily schedule for passenger flights in the U.S.," Mark Duell, FlightAware's VP â?? Operations, says in a Friday e-mail to Today in the Sky. "It was the fifth worst day for flight cancellations we've seen in the last 3 years after the Groundhog Day Blizzard (of 2011), Hurricane Irene (2011), and Superstorm Sandy (2012)."

Friday's recovery was expected to be especially challenging for the airlines. Many planes and crews remained out of place Friday morning -- a lingering result from all the cancellations, delays and diversions suffered on Thursday and throughout the week.

For those who still hope to take flight, airlines waived change fees and relaxed rebooking rules for customers ticketed to fly through stormy airports, though the precise details varied by airline.